Katelyn
I have a great life as a MAAB identifying as NB. Because this is my identity and I understand and accept this, it is the only way I can be authentic. However if your question is really asking whether a MTNB can express themselves in a way that provides a 'decent ' outcome, then this could depend upon a whole range of factors -
If your level of physical dysphoria requires minor changes, gender cues, removal of emotional dissonance and minor feminisation then this an absolute no brainer
If you are gender fluid then this will require some management and care but is still very achievable
If your target presentation is androgyne with a feminine spin then this will be more challenging and will require more thought and care
If you are gender queer this has been a very successful identity and expression for many non binaries. The extent that you wish to mix and juxtapose binary elements is only limited by imagination and comfort
To Ativan's point, being born male and identifying as NB is quite common and certainly successful for many. However, as with binary transitions, there are elements of risk, personal comfort and safety which we need to be aware of.
As an aside there appear to be many MAAB who either mistakenly felt they were MTF and others who knew they were NB who deliberately physically transitioned MTF before presenting as NB. Some of the first and some of the second group may feel that their first transition was unnecessary, while others may have a very different view.
No person is wrong or right. It is their life and their journey. If you have been born male and identify as NB, it is your narrative and your journey. There is no right or wrong speed, direction, destination or expression. The only right path is the one which you choose and which you own. Ideally it should be the one that truly works best for you, rather than a response to prevailing trend, majority view, peer pressure etc
Safe travels
Aisla